The COVCO-Basel study, which includes over 13,000 participants, is investigating the long-term health and societal effects of the COVID-19 pandemic on the adult population of the Canton of Basel-Stadt and the Canton of Basel-Landschaft. Since July 2020, participants were surveyed at regular intervals starting from July 2020 as part of the study, in order to investigate the effects of the pandemic. The researchers involved in the COVCO-Basel study - which is being conducted on behalf of the health departments of the Canton of Basel-Stadt and the Canton of Basel-Landschaft - published the latest results in a scientific report from July 2020 to August 2021.
People from low-income households more severely affected
The COVCO-Basel study includes an in-depth investigation of the mental health of the Basel population. It has shown that symptoms of depression have become more prevalent, particularly among study participants who have a low-income and among younger, female participants.
"What we are observing is that these individuals were exhibiting pronounced symptoms of depression early on in the pandemic, that these symptoms continued to worsen over time, and that even by mid-2021, they still had not returned to the level they were at the beginning of the pandemic," said Nicole Probst-Hensch, Head of the Department of Epidemiology and Public Health at Swiss TPH and principal investigator of the COVCO-Basel study. By contrast, people who have fewer financial worries and a higher-income, and who are predominantly male, exhibited lower levels of depression symptoms throughout the pandemic. People with a low-income who took part in the study generally had a lower quality of life in terms of their mental and physical health, social well-being and satisfaction with their living environment.
The participants were also asked what they were most worried about during the pandemic: "What they worry about the most is not being infected with the coronavirus or that people close to them could become infected. By far the most worrying thing for the participants was the restrictions on travel and cultural events," said Probst-Hensch.
Effect of a COVID-19 infection on ability to work
The COVCO-Basel study revealed the impact of the pandemic and the associated containment measures on the workforce. 10% to 15% of employed participants reported that they were working more than before the pandemic. In particular, participants who were working from home were working more than they did at their usual workplace and were often also working on weekends. For people who had to stop working because they were infected with COVID-19, the period of inability to work lasted between one and two weeks in most cases, but in 10% of cases, it lasted a month or longer. The longer a person was unable to work during the initial period of illness, the greater the risk that they would become unable to work once again. Data on this was recorded in cooperation with the Faculty of Law of the University of Basel.
High proportion of the population with SARS-CoV-2 antibodies
The COVCO-Basel study is also part of the antibody study of the Swiss-wide research programme Corona Immunitas. The antibody status of around 3,000 people from the cantons of Basel-Stadt and Basel-Landschaft was determined through blood sampling. As of August 2021, almost 90% of the participants reported that they had been double-vaccinated. While the rate of reported double-vaccination was the same in Basel-Stadt and Basel-Landschaft for those aged 50 to 64 (87%) and over 65 (94%), it differed for those aged 18 to 49 with 82% for Basel-Stadt and 75% for Basel-Landschaft.
The increase in the number of vaccinated people in 2021 is also reflected in the increase in positive antibody tests in the Basel region. By the middle of 2021, about 75% of those under 65 had antibodies against Sars-CoV-2, and in those over 65, the figure was over 90%. This increase is similar to increases observed in other cantons. However, these figures should be viewed with caution. "Since the study was somewhat less successful in reaching people with a low-income, and since these people are often less likely to be vaccinated against the coronavirus, these relatively high vaccination rates are probably an overestimate with regard to the population as a whole," explains Nicole Probst-Hensch.
About the COVCO-Basel study
The COVCO-Basel study is conducted by Swiss TPH and is co-financed by the cantons of Basel-Stadt and Basel Landschaft. The COVCO-Basel study consists of two cohorts: a seroprevalence cohort of around 3,000 people (participation involves blood sampling for antibody tests and answering digital questionnaires) and a digital cohort of around 10,000 people (participation involves answering digital questionnaires). The study has been running since July 2020 and is designed as a long-term study whose purpose is to investigate the health-related and societal effects of the pandemic and the associated containment measures on the population of the Basel region.
COVCO-Basel is part of the Swiss-wide research programme Corona Immunitas, which is conducted by the Swiss School of Public Health (SSPH+). Corona Immunitas is a research programme designed to measure the extent of SARS-CoV-2 immunity. Although the part of the study that is centrally coordinated by Corona Immunitas will be reduced at the end of the year, the COVCO-Basel study will continue. Plans for the future of the study include the incorporation of health examinations and environmental measurements. The COVCO-Basel study aims to help create a living and residential environment conducive to a high quality of life for the people who live in the region.
"The COVCO-Basel study is providing important insights into the impact of the COVID-19 pandemic and is helping us to continue to combat the coronavirus in an evidence-based manner. Therefore, on behalf of the Health Department of Basel-Stadt, I would like to thank all those involved and especially the around 13,000 participants who made this important study possible in the first place," said Cantonal Physician Thomas Steffen, Head of Medical Services of the Health Department of Basel-Stadt.
"We are truly impressed with the results of the COVCO study. For us, a key factor in the success of the study was the fact that it was embedded in the national research programme from the beginning," said Jürg Sommer, Head of the Health Department of Basel-Landschaft.